


your blood knows the way (from your heart to your brain)

by Cerberusia



Category: Teen Wolf (TV)
Genre: Multi, Pack Dynamics, Pack Family, Pack Feels, Pack Hale OT4, Polyamory, Pseudo Incest, Sharing a Bed
Language: English
Status: Completed
Published: 2013-01-05
Updated: 2013-01-05
Packaged: 2017-11-23 18:53:09
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,894
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/625463
Author URL: https://archiveofourown.org/users/Cerberusia/pseuds/Cerberusia
Summary: <blockquote class="userstuff">
              <p>Erica and Isaac share <i>everything</i>.</p>
            </blockquote>





	your blood knows the way (from your heart to your brain)

**Author's Note:**

> This was originally written for TW Hols, for verbyna. I loved writing it (Poly!Pack is my one true ship for this fandom), and I hope to write a lot more in this 'verse because my feels for this ship are OUT OF CONTROL.

Erica and Isaac share _everything_.

They knew each other before the Bite in only the vaguest way: a recognisable face from school who ended up in the ER at three in the morning, exchanging the nods of people who knew that they were going to be seeing a lot of each other in there. They never talked, though; didn't talk to anyone, really.

Then the Bite happened, and it was like a switch being flipped. The minute they saw each other, they recognised each other - as siblings, maybe. Littermates. Later, people will take to calling them 'the twins', and they'll take the nickname gladly. It's a scent thing, maybe - Peter tells them once that they smell like one another - but at the time they just dive towards each other like puppies being introduced and proceed to sniff each other - before realising what they're doing and skittering away, embarrassed. Derek looks exasperated, but Isaac thinks he might be slightly amused. He hopes so, at least.

They get over the awkwardness quickly though, simply because they can't stay standoffish around each other - they (feel like they) know each other too well. Isaac can't compare it to Camden because they were never close - eight year age gaps and the elder sibling fleeing the nest as soon as they turn eighteen will do that - but Erica knows it's not like it is with little Julian, whom she loves as an older sister but could never fathom having this kind of instinctual _knowledge_ of. So twins it is.

But does a twin curl around you as you jerk off, hand on your shoulder, your forearm? Do they help, cupping your breast in their palm, sliding a finger inside you? Maybe they do; Erica and Isaac wouldn't know.

_We're mythical creatures of the night,_ says Erica, nuzzling the side of Isaac's neck, touching her mouth to his pulse, _We make our own rules._

So that's how it starts: Erica&Isaac, too close for lovers, too close for anything but.

~*~*~

Or maybe it starts before then, before Erica is even given the Bite. Maybe it starts when Isaac's father is killed and the first thing he does is seek out Derek and Derek lets him sleep there, with him, not even in a totally platonic, victim-of-circumstance, there's-only-one-bed-way, but pressed hot against Isaac's back. He's gone when Isaac wakes in the morning, but when he opens his eyes briefly in the early hours, Derek's face is buried in his neck, an arm tight around Isaac's waist, like he's a teddy bear.

Isaac's too tired and freaked out by his dad _being murdered_ and then _being arrested for it_ to have a secondary freak out about this, and by the time he's back in the depot after his first full moon, human again in the weak morning sunlight, wrapped up in Derek's sheets that still smell of him, he can't really be bothered. He figures it's a wolf thing, like how puppies sleep all piled on top of each other. Nothing weird. The fact that being in Derek's bed, surrounded by the smell of Derek, makes him hot? Probably kind of weird, but whatthefuckever, _werewolves exist_ and he just turned into one. That kind of thing puts minor shit like this into perspective.

He's half-hard and kind of wants to jerk off, wrapped up in warmth and that smell, but even given the werewolf thing, he figures that would be rude. He rolls onto his stomach and presses his hips into the mattress; not with any intent, just taking the edge off. He just feels so _comfortable_ , the kind of comfort that's more than physical. Like he's meant to be in his Alpha's bed.

When he opens his eyes again, Derek is standing in the doorway looking at him. Just looking, in a way which one might call admiring but Isaac would call assessing, because people don't admire him. Derek eyes him up like this for a few seconds, then turns away, leaving him to his own devices.

For the first time, Isaac doesn't feel that he's found wanting.

~*~*~

The thing about Erica and Isaac is that it's very easy for her to convince Isaac to do stuff. In fact, for all he may appear suspicious and even downright wary - and he is - it's actually very easy to convince Isaac to do stuff in general, if you know the right buttons to push. It's how she gets him to come for ice cream at two in the morning, to double-team some unsuspecting stranger with flirting, to let her try out new eyeliner techniques on him. She once even manages to get him into a pair of her panties, which fit because he's tall but he's skinny, and even becoming a creature of the night can't change basic body type. He doesn't seem to mind, though, so neither does she.

The panties are royal purple, bikini-cut and apparently more lace than cotton, and it takes every ounce of Isaac's newfound self-confidence for him not to just die from sheer mortification as he puts them on. What's the point, he doesn't even look like a girl, couldn't pass if he tried (much later, he'll find out that that's not true - but that's a tale for another time). He looks stupid and he knows it.

Erica's looking at him like he's a birthday present. He can smell her cunt from here. She pats the bed beside her and he sits down gingerly, folding in on himself out of habit - and promptly gets forced upright as she climbs into his lap.

She's not wearing any underwear. He suddenly realises why this pair smell so strongly like her, and feels his ears flush. She rests her forehead against his and grins a secret grin. Tentatively, he smiles back, showing teeth.

~*~*~

It takes a little longer for Boyd to integrate fully: years of loneliness have made him naturally aloof, and his quiet and reflective nature is at first confusing and offputting. The twins don't know how to approach him, so they circle him and he just watches them, face relaxed and inscrutable. Even with the pack-bond pulsing between them all, it takes a fortnight for them to coax him into curling up with them - the three of them finally make a real puppy pile. Erica is always in the middle, her boys on either side of her like sentinels or guard dogs.

Isaac doesn't know how he feels about fucking around in front of Boyd, but Erica takes care of that for him one afternoon by casually brushing her fingers over her nipple through her clothes, gently, then with intent a few times, before taking Isaac's hand and moving it to cup her breast. Isaac, lying behind her, pinches the nipple out of habit while she splays her hand out over her abdomen, rubbing lazy circles under her navel with her thumb. Her other hand slips between her thighs to stroke lightly at the skin there, then works higher, under her skirt, and Isaac knows when she reaches her clit because her hips roll forward. He buries his nose and mouth in her neck, nuzzling a little.

Boyd is just watching them, eyes bright and unblinking, just an inch away on the pile of mats just barely insulating them from the cold subway floor. Isaac wants to know what he smells like right now, but doesn't want to stop kissing Erica's neck, so he keeps his nose where it is and fixes Boyd with his eyes. Plays a little more roughly with Erica's tit, licks a stripe up her neck - and never takes his eyes off Boyd's. He can feel himself heating up, pinpricks of arousal flaring low in his stomach, and the thought that Boyd might be able to smell that, distinct from Erica's arousal, gets him going more than he thought it would. A _lot_ more. He rocks his hips against Erica's ass and feels her press back against him, perfectly in sync.

Erica gasps and sighs her way to orgasm, body warm and familiar under his hands, then rolls over to stroke his thigh and bite the curve of his neck while he jerks off. The whole time, his eyes never stray from Boyd's.

~*~*~

Isaac comes back after lacrosse practice one day to find Erica fucking Boyd on their ratty green sofa. For the first time, he doesn't know what she wants him to do. He settles for slipping into the compartment which serves as his room when Derek doesn't feel like co-sleeping, giving them the human semblance of privacy though he can still hear and smell them just fine.

It's...surprisingly awkward. If they'd done it together, worked as a team like they have in the past, he'd be fine with it; but Erica striking out on her own, without telling him, without telegraphing her intentions, is weird.

Or maybe she did signal it. Maybe he can't read her any more - and that thought makes his stomach turn over in something like nausea and something like grief, so he stops thinking about it, puts his iPod in and tries to do his Physics homework. He doesn't actually like Physics, but trying to keep a passing grade in it beats listening to them; inside the train car, outside the pack.

He keeps expecting Erica to stride in, flushed and happy, to flop all over him and share her warmth with him - but after a while, even through his music, he hears them leave the depot, the sharp click of Erica's heels in counterpoint with the steady thud of Boyd's boots.

He feels both hollow and too full. He swallows against the hot, uncomfortable sick-sadness and, giving up on trying to concentrate on the tensile strength of a spring, steps into the next traincar, where Derek usually sleeps. He's not here right now, which is fine by Isaac because he'd never gather up the courage to do this if he were. He's a little worried about what he'll do when he gets back, but not enough not to do it.

Slowly, he lays himself down on Derek's bed - more a nest of pillows and blankets, really, like his has become since the bite - and wraps himself up in Derek's scent: the first scent he ever learnt with his new enhanced senses. It doesn't work perfectly, because Derek's not actually there to snuggle with and his bond with Erica's all twisted up, but he stops feeling like he might cry - he told himself he wouldn't, any more, because terrifying, bloodthirsty creatures of the night don't do anything as pathetic as weeping - so he counts it as a win.

He drags himself reluctantly out of the cocoon of blankets half an hour later, very aware that Derek could return any moment. He doesn't know what might happen if he's caught.

Derek doesn't say anything when he gets back, even though Isaac's scent must be all over the sheets. Isaac sleeps restlessly that night, mind stuck on Derek, alone in his bed, surrounded by the smell of Isaac.

~*~*~

Erica makes it up to him, of course. He's been trying to give her and Boyd some privacy to let them work out their relationship in peace and let himself come to terms with the inevitability of Erica growing apart from him. He watches them out of the corner of his eye and tries to read her thoughts from the tilt of her neck, like he always used to. He still understands that, the language of her body, but he can no longer read her face. They're no longer in sync, and it throws him more violently and yes, hurts him deeper than he wants to admit. He'd got used to having a twin so quickly; but then, even identical twins can grow apart.

But she notices, of course - and what's more, she fixes it.

"Derek told me what to do," she says, after she's sought him out and curled up against his back, arms around his waist, head pillowed on his shoulder. He can't imagine his bony shoulders make particularly comfortable pillows, so he takes it as being more for his benefit than hers.

"For what?" he asks, fiddling with a bit of her hair.

"For getting us back in sync." She turns her head so her chin now rests on his shoulder - which must be very uncomfortable indeed - and her breasts press into his back. Well then. He puts down _The Outsiders_ and lets her hitch up the hem of his t-shirt to stroke her thumb over the curve of his bottom ribs.

"Really?" he asks, interested. "Derek told you that sex would fix it?" They've never actually referred to what they do together as _sex_ before, and it feels strange to call it that. Sex has oral and penetration and kissing on the mouth. They just - mess around. Help each other out.

"Not sex," she says. "Just what we usually do." Her hand slides higher, splaying flat over his chest.

"I'm trying to imagine how that conversation went," he admits. Erica snorts.

"About as smoothly as you'd expect," she says. "Short sentences, didn't look me in the eye." She pushes him down to straddle him for a moment, just looking down at him with warmth in her eyes that makes him feel warm too, then slides off to lie next to him, both of them on their sides, noses nearly touching. She twines their fingers together and moves to nuzzle his neck; he does the same to her. He breathes in, deeply.

Derek's in the depot, he knows: if he concentrates, he can hear his steady heartbeat. But he's not bothered about Derek right now, too busy losing himself in the feel of Erica's thigh in his hand. She likes her ass and tits squeezed, so he does that for her while she gets herself off with one finger inside herself and her palm grinding her clit, just how she likes, licking and biting Isaac's neck in between sighs. She keeps doing that as Isaac starts to jerk off - she knows his neck's sensitive and uses that ruthlessly to her advantage - along with stroking and pressing lightly at his perineum. A bit of his come gets on her skirt, which she'll complain about later when she realises, but will be secretly a little pleased by because it means she'll smell like him just a little more strongly.

(Just after his orgasm, Isaac is dimly aware of Derek's heartbeat spiking erratically, his laboured breathing clear to Isaac's ears. He deliberately pushes the knowledge and implications to one side. One emotional crisis at a time).

~*~*~

They ask him to run with them. They love Derek in the way you must love your Alpha, the same way you must love your parents, but he's not a _good_ Alpha, they say. There are other packs out there, bigger packs, more experienced packs. They can do better than Derek.

Isaac knows. He knows, intellectually, that Derek has fucked up. He fucked up by even turning a bunch of teenagers in the first place. He wanted soldiers; he got juvenile delinquents. He broke Isaac's arm, just like his Dad did twice, to teach him not to talk back. He fucks up because he's _been_ fucked up; Isaac recognises the cycle because he perpetuates it himself. He knows what it's like not to be able to stop; maybe not _wanting_ to stop.

He wants to say yes, let them take him with them. The three of them against the world, searching for a new pack. The three of them, loving each other because that's what Pack does. They'll never exclude him again.

But then he thinks of Derek's arm around his waist, Derek's breath on the back of his neck - the notion that he might never wake up to that again stirs that same grief in his belly.

So he goes to Scott, because he doesn't really have anyone else and it seems like a good idea at the time. He doesn't even have Scott, not really, but the look on his face and the brush of his fingers when he handed over the needle make him think that maybe he could. Scott gives pieces of himself out all the time: to his friends, to his girlfriend, and to complete strangers like Isaac. Because he is, as Isaac rapidly comes to understand, a _nice person_. Now, nice people aren't so rare; Isaac's even met a few - then promptly avoided them, just in case. Just in case what? Just in case they turned out not to be nice after all, in case they figured it out and tried to help but just made things worse, in case they got to know him and decided he wasn't worth it, too pathetic even for them.

This time, Isaac's seizing his chance.

~*~*~

When Isaac wakes up in Derek's bed again, this time with Derek still in it, he does jerk off. It's stupid, after Derek's made it plain that he's not interested in fucking his betas - or anyone at all - and Isaac's pretty lucky to be sharing his bed even in a platonic sense. But he does it anyway, because Erica and Boyd are gone and Derek's bed is the only place he can find that sense of pack, of _rightness_.

He doesn't even try and do it furtively or quickly, like he's ashamed - they're back to back, but he knows that Derek can hear and smell him, and that's fine. He's not embarrassed by the idea of Derek knowing.

In fact - he reaches into his underwear and slowly traces the vein on the underside of his dick, and shudders, knowing that Derek will hear the rustle of fabric and the hitch in his breath. He's half-expecting Derek to get up and leave, but he doesn't. The other side of the bed-cum-nest stays still. He can feel Derek's body heat emanating through the inch of space between them.

He's not loud or anything - a bit of heavy breathing and that's it - and he can hear with perfect clarity Derek's heart beating slightly too fast in his chest. Now, there's lots of things which could do that - anger, for a start - but when Isaac breathes in through his nose, he can smell something spicy and musky rolling off him, and he knows _exactly_ what that is.

He's not surprised when Derek finally moves - but not, as Isaac had expected, to get up, but rather rolling towards Isaac, solid, searing heat all the way up his back. He buries his nose in Isaac's neck for one, two, three seconds before pulling away like he's been burned and fleeing the room before Isaac can even roll over to see.

No use going after him, Isaac decides, so he squirms onto Derek's side, where his scent is stronger and still warm from his body, to finish jerking off. He has his priorities. Derek can come to him when he's sorted out his.

~*~*~

(Peter finds him afterwards, back at the house. It's dangerous for them to be there with the Argents on the prowl, but forward-thinking in the face of overwhelming emotion has never been one of Derek's more prominent attributes. He tells him so, leaning casually against the half-destroyed stairs, and Derek just snarls at him.

"It's perfectly normal, you know," he says. "If he were born rather than bitten-"

"Shut up," says Derek.

"-you'd have taken him for his coming-of-age anyway," Peter continues, as if Derek hadn't spoken. "Besides, you were younger, and we did far more than _that_."

"Shut up," says Derek again.

Peter shrugs his just-saying shrug and leaves him to it. Derek's always been so _melodramatic_ ).

~*~*~

Erica and Boyd return within a week of their departure, dirty and shaken, but otherwise unhurt. They stink of other wolves, powerful wolves: the Alpha pack. They're the message, though they don't know it. They turn up on the porch at dawn, clutching each other's hands, and Peter's the one to let them in. They narrow their eyes in tandem, confused by this stranger who smells like Pack, but Isaac comes hurtling down the corridor before they can commence introductions and awkward questions. He's only just woken up, and his hair is sticking up on one side. Peter melts discreetly into the shadows and lets the pups have their moment.

Erica and Boyd look like they're steeling themselves to give explanations, but Isaac doesn't really care right now. What he cares about is that they smell like a different pack, the _wrong_ pack, and that needs to be changed. They could do with showers for a start, but since the Hale house doesn't have running water and neither of them look like they could cope with a dunk in the creek, they'll have to skip right to the marking part.

Isaac doesn't mind. That's his favourite part. He's pretty sure it's Erica's and Boyd's too: they're flinging their clothes off before they even get to the study which has been converted in short order into a downstairs bedroom because the entire upstairs is uninhabitable. They land together in the nest of blankets and pillows that smells like Derek and Isaac because they've been sleeping in it for a week, chastely but pressed tight together because they can't stand to sleep apart when they're all the pack they've got left.

But no longer. They wrap around each other as close as they can, trying to cover one another with their scent. Isaac licks the back of Erica's neck and Boyd, in an unusual and unexpected display of tenderness towards him, kisses his calf. They don't dislike each other, or anything - they just don't know each other properly yet, either in mind or body.

That's something that Isaac would like to change. Maybe he will, in the morning. For now, he just nuzzles as close to his packmates as he possibly can, getting rid of the stranger-smell and replacing it with his and their own.

But there's still something missing. Someone.

"Derek," he says, quietly, " _please_."

And Derek does. He climbs into the nest and attempts to cover them all with his body. It doesn't quite work, for obvious reasons, but when Isaac, sandwiched in between Boyd and Erica, feels Derek's warm weight settle on him he feels - full, maybe. Even perhaps complete.

He watches Derek brush a lock of hair out of Erica's face - another small, unexpected tenderness. He can't see Derek's face, which is probably for the best - he might do something stupid, like try to kiss him.

He wants to kiss Derek. What a strange thought. But then he'd also like Derek to kiss Erica, and Boyd too; and this time he thinks he'd enjoy seeing Boyd and Erica together, and maybe he could even be involved. Erica and Isaac do, after all, do everything together. He doesn't know about Jackson yet (see if finally becoming a werewolf and being exposed to pack bonding lessens his intrinsic douchebaggery any), but he definitely wants Scott in there somewhere too - but he doesn't know how to quantify that yet and anyway that's not going to happen for a long time, if ever, so he concentrates on the tiny wishes. Concentrates on the knowledge that he's going to wake up tomorrow morning in the arms of his pack, Alpha included, and he's going to be _happy_.


End file.
